Darwin’s theory of evolution through natural selection is an explanation of biological adaptation. At the time that Darwin was developing his ideas, natural theologians (e.g., Paley, 1836) emphasized that organisms are eminently well designed for habitats they occupy. They reasoned that the existence of design required a conscious designer and, hence, inferred the existence of a Creator. Darwin’s (1859) theory explains how organisms can become adapted to their environments over evolutionary timescales through a material process involving no conscious designer, one he named natural selection.